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Do pH levels and cancer have a connection?
The popular assertion can be found all over the internet, and one particular Facebook post shares an unattributed quote that makes the bold claim that "every" person with cancer has a pH that is "too acidic." It then goes on to say that the late Dr. Otto Warburg, a renowned cancer researcher, won the Nobel Prize for proving that acidity-cancer relationship.
The post begins with the quote: "Every single person who has cancer has a pH that is too acidic," and then goes on to say that Warburg "won the Nobel Prize in 1931 for proving that cancer can’t survive in an alkaline oxygen rich environment but thrives in an acidic, low oxygen environment."
The post was flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Facebook.)
Let’s cut to the chase: This isn’t accurate.
Dr. Otto Warburg did, indeed, win the Nobel Prize in 1931, but not for proving that cancer and pH levels are related. And cancer does, indeed, thrive in an acidic environment – but it’s not that cut and dried.
According to the Nobel Prize website, Warburg was awarded the prize for his discovery of the "nature and mode of action of the respiratory enzyme." A discovery, the website says, that "opened up new ways in the fields of cellular metabolism and cellular respiration. He has shown, among other things, that cancerous cells can live and develop, even in the absence of oxygen."
Warburg’s research eventually found that cancerous cells helped produce the low-oxygen, high-acidic conditions – not that they were necessarily created out of such an environment.
That pivotal discovery, now termed the "Warburg Effect," is the observation that cancer consumes glucose and excretes lactate. A 2016 medical report on the Warburg Effect explains the process:
"When oxygen is present, normal cells use mitochondria to oxidise glucose, but in the absence of oxygen, glucose is converted into lactate. Otto Warburg first described in the 1920s that cancer cells utilised higher levels of glucose in the presence of oxygen with an associated increase in lactate production."
Another 2016 review, found in the Trends in Biochemical Sciences journal, says that the Warburg Effect is better identified as part of cancer’s progression and not the initial onset of the disease:
"It is likely that the Warburg Effect provides an overall benefit that supports a tumor microenvironment conducive to cancer cell proliferation. However, the Warburg Effect is thought to be an early event in oncogenesis that is an immediate consequence of an initial oncogenic mutation."
So, the meme gets it a little twisted – while Warburg found that cancer cells certainly survived and grew in acidic environments, they also helped create those environments.
"All of this basically means that malignant tumors tend to be low in oxygen and that cancerous cells, more than normal cells, metabolize sugars in a way that does not rely on oxygen, which in turn produces an acidic micro-environment," Ted Gansler, strategic director of pathology research at the American Cancer Society, told PolitiFact.
"This does not mean that a cancer patient’s entire body is acidic, only the tumor is. Also, growth and metabolism of the tumor causes low oxygen levels and an acidic environment locally, but this definitely does not mean that an acidic environment or low oxygen level caused the cancer or that eating an alkaline diet or breathing air with higher levels of oxygen can effectively treat the cancer."
It’s also worth noting that the claim doesn’t define what it means by "too acidic." According to health information website Healthline, the pH value varies from 0 to 14, with "acidic" ranging from 0 to 6.9, "neutral" at 7.0 and "alkaline" between 7.1 and 14. The pH levels in the human body also vary. For example, the stomach is highly acidic to aid in digestion, while blood is slightly alkaline. Even more importantly, while diet can alter the pH levels of urine, it does not significantly affect the pH of a person’s blood.
Drawing from several studies found in the U.S. National Library of Medicine National Institutes of Health, the Healthline report points out the main reasons why this acidity and cancer connection is flawed:
"Firstly, food doesn’t significantly influence blood pH. Second, even if you assume that food could dramatically alter the pH value of blood or other tissues, cancer cells are not restricted to acidic environments. In fact, cancer grows in normal body tissue, which has a slightly alkaline pH of 7.4. Many experiments have successfully grown cancer cells in an alkaline environment. And while tumors grow faster in acidic environments, the tumors create this acidity themselves. It is not the acidic environment that creates the cancer, but the cancer that creates the acidic environment."
"(An alkaline) dietary pattern is effective because it provides beneficial nutrients, avoids harmful substances that can cause cancer, and avoids excess calories that can lead to obesity, which is itself a risk factor for cancer, heart disease, and type 2 diabetes" Gansler said. "The benefit of these foods has nothing whatsoever to do with their pH (the way scientists describe alkalinity and acidity). In fact, the pH of blood and tissues remains remarkably constant and is not influenced by diet. To be blunt, the rationale behind an alkaline diet is ‘pseudoscience.’"
Maria Petzel, a senior clinical dietitian at MD Anderson Cancer Center at the University of Texas, explains in a Q&A on the center’s website that the alkaline diet is based on a theory that eating certain foods can change the body’s pH levels:
"Some believe that changing the body’s pH levels can improve your health and help you lose weight or even prevent cancer. But there’s no way the foods you eat can alter the pH level of your blood," Petzel says in the Q&A. "The body’s pH is a very tightly regulated system. If you change your diet, you may see changes in the pH of your saliva or urine because these are waste products, but there’s no way you could ever eat enough that it really impacts your blood."
A claim recently posted on Facebook says "every single person who has cancer has a pH that is too acidic" and that Dr. Warburg’s research proved cancer cannot survive in an alkaline environment.
The human body’s pH varies, so it is not possible for a person to simply have a universal pH that is "too acidic." And while it is correct that cancer thrives better in acidic conditions versus alkaline, cancerous cells are known to help produce the acidic environment themselves.
We rate this claim False.
Correction: Dr. Otto Warburg won the Nobel Prize in 1931, not the Nobel Peace Prize. This story has been updated.
Facebook post, July 5, 2019
NobelPrize.org, Otto Warburg Biographical, Accessed July 9, 2019
Healthline, The Alkaline Diet: An Evidence-Based Review, Accessed July 9, 2019
PubMed.gov, The Warburg Effect: How Does it Benefit Cancer Cells? March 2016
PubMed.gov, The Warburg effect: 80 years on, Oct. 19, 2016
AfricaCheck.org, ‘Every single person with cancer has pH that’s too acidic’? Meme gets old science backwards, May 29, 2019
University of Texas MD Anderson Cancer Center, Alkaline diet: What cancer patients should know, April 2, 2018
American Institute for Cancer Research, Alkaline diets, Accessed July 9, 2019
Email interview, Ted Gansler, strategic director of pathology research at the American Cancer Society, July 12, 2019
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